We did another run a few months ago. @astosia made some design changes so that the internal stamped sheet metal snapped into place better, and we asked ProtoTi to tap the threads to be M1.2. (I sure did NOT have any interest in tapping M1.2 threads in titanium myself.) Inexplicably, I apparently didn’t bother to take any photos, but they arrived on December 1st.
But the real excitement was that I found a vendor on Alibaba that would make a reasonable quantity of buttons for us! We got some custom press-in buttons to our specification. On December 29th, a reasonable quantity of custom buttons arrived.
You know, a reasonable quantity. Like… 200 of them.
The buttons didn’t quite press in. It turns out that you need to specify a press fit worth of tolerances if you want a press fit. You learn something new every day! So I bought some reamers, and off I went to take the shells over to my friend Craig’s house to use his drill press. His shop cat, Mina, came to help out.
I processed all the holes to make sure they were good and round:
And at last, I had holes that the buttons fit into. Unfortunately, they fit… with a clearance fit. Grr. I ordered some Loctite 680, which is a particular retaining compound exactly designed to hold metals in place for clearance fits.
Of course, since the buttons were steel, I couldn’t install the buttons until all the titanium had been anodized. I wanted to try doing some mask work this time, and I wanted to experiment with various other surface finishes – I wanted to do a brushed finish, and I was hoping for some high voltage pinks. Well, the masking didn’t go so well, and neither did the high voltage finish! I didn’t get the sharp lines I wanted, and the paintbrush I used to paint on electrolyte also plated some other junk metal onto the part, and also, I had some contamination so no matter how much current I stuffed into it, I was definitely not going to get up to those 70V colors. It looked like I was going to have to actually get serious about etching contaminants away in advance. In for a penny, in for a pound – I ordered a bottle of Multi-Etch.
I grumbled, and started to polish off the previous attempt at an anodization. I did get one reward for it, though: since I put a brushed finish on the part before, when I lightly polished, I first polished the tops of the ridges, and left the anodization deep into the brush marks! The result is that I got a very interesting anisotropic finish – if you look at it straight on, you get color, but off angles, you get the shine from the tops. The process was not well controlled in this case, but you could see what I was going for, and what sort of effects were possible – some very angle-sensitive pastels.
I grumbled at this project having taken over my kitchen table for much longer than I had wanted, and waited for my bottle of Multi-Etch to arrive in the mail.
. Good luck with the project!